Choke for gun barrels



Dec. 29, 1953 E. F. WHITE 2,663,961

CHOKE FOR GUN BARRELS Filed July 7, 1950 Bnventor Patented Dec. 29, 1953CHOKE FOR GUN BARRELS F. White, deceased Application July 7, 1950,Serial No. 172,456

10 Claims. 3

This invention relates to a choking device for firearms such as shotguns and more particularly to an adjustable choke device which may beautomatically adjusted in response to the firing of the gun.

A choking device for a gun serves to control the shot pattern of the gunand more particulariy the s read a the shot at any given d stance fromthe muzzle. It is, of course, desirable to employ a choking device whichis adjustable so that variations between an unchoked condition and afully choked condition may be provided depending on the type of game forwhich the gun is being used. Moreover, it is sometimes desirable to varythe degree of choking action at to provide for automatic adjustment ofthe choking device to further constrict the muzzle upon the firing ofthe first shot so that the proper choking effect will be obtained forthe second shot.

A choke device of the general type described above is illustrated in thepatent to Egleson No.

2,453,747, granted November 16, 1948, and it is contemplated by thepresent invention to provide a gun choke which is an improvement uponthat shown in this patent.

As illustrated the present device comprises an extension applied to thegun muzzle, the extension being provided with, longitudinal slotsextending through its free end and a constricting sleeve is threadinglymounted upon the extension, the extension and sleeve being provided withcooperating means so that rotation of the sleeve serves to restrict theextension and thereby choke the gun. The amount of constriction ordegree of choke depends upon the threaded adjustment of the sleeve in aclockwise direction (when facing the gun muzzle) on the muzzleextension. Suitable projections are provided in spaced relation on therear end of the sleeve to extend rearwardly therefrom and a stop memberis provided on the extension to extend between and be engaged by theseprojections. This sto member is spring pressed into position to engagethe extension but may be drawn to dis-engaging position against thtension of the spring and, when moved to such a position, the sleeve maybe manually adjusted to any desired position. In practice this would bethe position desired for the first shot to be made with the gun and uponthe firing of this h t the s e ve Woui be r tated by the explosion gasesso that the next adjacent projection would be engaged by th stop memberand thus the sleeve would be moved to a position to effect a greaterdegree of choke for the second shot.

The projections on the sleeve are spaced apart to a sufficient extent toallow rotation of the sleeve through a sufficient angle to efiect thedegree of diiference in choking efiect which would normally be desiredbetween the first and second shots fired by the gun. At the same timesulTi-' cient of the projections are provided so that the device may beset at the desired choking position for the first shot depending uponthe desire of the user. Thus, the device may be manually set for anydesired choking effect (except, of course, full choke position) and ateach of such settings would give the user substantially the same serviceas that given by a double-barreled gun, one barrel of which isconstricted more than the other.

Also at the same time the device may be set to any adjusted position andprevented from moving from that position if a constant and uniformchoking elfect is desired.

One object of the present invention is to provid a new and improvedadjustable gun choke.

A further object of the invention is to provide a gun choke which mayreadily set and retained in any desired adjusted position and which maybe moved from this position to a different predetermined adjustableposition by the firing of the gun.

A still further object of the invention is to provide an improved gunchoke consisting of a gun barrel extension and a sleeve rotatablymounted thereon to efiect constriction of the extension and cooperatingmeans on the extension and sleeve to permit adjustmentof the sleeve toany desired position in which it will be held against accidentalmovement in one direction, but which will be left free for movement inthe opposite direction by the expanding gases upon discharge of the gun.

A further object of the invention is to provide an adjustable chokingdevice which may be moved from one position to another by the dischargeof the gun and which shall be provided with improved means forreleasably holding the parts in adjusted position.

To these and other ends the invention consists in the novel features andcombinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of the muzzle end of a gun barrelhaving my improved choking device applied thereto;

Fig. 2 is a sectional view on line 2-2 of Fig. 1;

Fig. 3 is an elevational view of the muzzle extension of the device withthe sleeve removed;

Figs. 4 and 5 are transverse sectional views on lines 4-d and 55 of Fig.1, respectively;

Fig. 6 i a partial elevational view of the device showing the parts inone adjusted position; and

Fig. 7 is a view similar to Fig. 6 showing the parts in another positionin which the sleeve is locked against movement responsive to the firingof the gun.

To illustrate a preferred embodiment of my invention, I have shown inFig. 1 of the drawings the muzzle end of agun barrel ill to which issecured a shell or muzzle extension member II. This may be secured tothe. barrel in any desired Way, such, for example, as by the screwthreads It may be noted that the internal bore of the shell H as shownat i3 is slightly larger than the muzzle bore of the barrel IE] so as topermit a slight expansion of the explosion gases of the gun when thispoint is reached. At its forward portion the extension is provided withlongitudinally extending slots it which open through the end of theextension and upon its exterior surface are provided annular camsurfaces It and i6 whereby, as will be hereinafter described, theextension may be constricted to effect various degrees of chokingaction.

A sleeve I6 is provided with internal screw threads 19 whereby it may bethreadedly attached to the exterior screw threads 20 adjacent the rearportion of the shell or muzzle extension ll. Internally this sleeve isprovided with annular cam surfaces 22 and which cooperate respectivelywith the cam surfaces l5 and 16 on the forward portion of the vmuzzleextension H so that as the sleeve is moved rearwardly by rotativeengagement of the threads 19 and 2!) the forward portion of the muzzleextension may be constricted, the degree of constriction varying withthe amount of rotation of the sleeve It in a clockwise direction whenfacing the muzzle of the gun, or in a direction to move the sleeverearwardly upon the extension I I.- This constriction of the muzzleextension is permitted by the slots It as is well understood by thoseskilled in the art.

Upon the forward portion of the sleeve l8,is an enlarged chamber 24which is constricted at its forward end to form an exit tube 25.

A plurality of longitudinally-extending slots 26 are provided in thechamber portion 24 of the sleeve. These slots extend through the wall ofthe sleeve at an angle to the radius of the chamber member, as shown inFig. 5, so that when the explosion gases pass therethrough a torque willbe imparted to the sleeve tending to rotate it in the direction of thearrow shown in Fig. 5 or in a direction tending to advance the sleeveupon the muzzle extension M. This rotation of the sleeve will be in aclockwise direction when looking toward the muzzle of the gun or in adirection tending to further constrict the sleeve member and thusprovide a greater degree of choke.

Furthermore, it will be seen that the walls of the slots 25 are notparallel, but that the trailing wall is cut away or relieved as shown at21 so that the expanding gases in passing through these slots will reactwith a greater force against the opposite edges and thus impart agreater turning torque to the sleeve topositively effect rotationthereof upon the muzzleextension in theproper direction to effect agreater degree of chokin action.

The non-radial direction of the slots provides vane-like segments 28between adjacent slots and the direction of the arrow in Fig. 5indicates the direction of rotation of the sleeve caused by theexplosion gases issuing through the slots.

Upon the rear end of the sleeve l8 are provided nubs or projections 30which project rearwardly from the sleeve along the exterior surface ofthe muzzle extension II. These projections are in spaced relation andwhile the number may be varied as desired, as shown six are employed andeach is marked with a number or other indicia 3[ to indicate to the userthe degree of choke provided by a particular setting of the sleeve.

Cooperating with these projections is a stop element secured to themuzzle extension as will now be described. The muzzle extension isprovided with an arcuate recess or groove 32 shown more especially inFig. 4 which extends around approximately three-fourths of thecircumference of the extension. Within this slot is disposed a springmember 33 of arcuate shape. One end 34 of this spring member is turnedinwardly in a radial direction and secured in an opening 35 in the bodyof the extension so that this end of the spring is anchored againstmovement. The other end of the spring is left free and is turnedoutwardly in a radial direction as shown at 3% and upon. this free endof. the spring is carried an adjusting button or fingerpiece 31.

The rear wall of. the groove 32 is relieved or cut back as shown at 39and 4D in Fig. 3, providing a shoulder 4| upon the rear side of thegroove. This permitsthe spring member 33 to be moved rearwardly at itsfree end, the sprin fulcruming about the shoulder 4| as shown in dottedlines in this figure.- It will be seen from Fig. 1

of the drawings that the free end 36 of the spring normally standsbetween the projections or nubs 30 and is engaged by these projectionsso as to limit the rotation of the sleeve with respect to the extensionmember I I. The operator, however, by pressing against the fingerpiece31 may move the end portion 36 of the spring rearwardly against thetension of the spring to the dottedline position shown in Fig 3-in whichthe end 36 of'the spring clears the projections 30 and permits freerotation of the sleeve 18.

The operation of the device is as follows. The user,- by moving thefingerpiece 31 rearwardly to dotted-line position shown in Fig. 3, maythen rotate the sleeve to the proper position to obtain any degree ofchoking action desired. If, for example, he desires only a small degreeof choke, the sleeve is moved to the position shown in Fig. 6 where theprojection numbered 1 is engaged with the end 36 of the spring, thelatter being on the right-hand side of .this projection as shown in thesectional view of Fig. 4. The sleeve is prevented from moving to. theright from this position, or from moving in a direction which willprovide a more open muzzle. It may, however, be moved to the left or ina direction to provide a greater degree of choke until the spring 36 isengaged with the next of the spaced projections 30 or that one markedwith the numeral 2.

In practice, the user sets the sleeve in the manner just described toprovide the proper choking efiect for the first shot to be fired. -Whenthis shot has been fired, the explosion gases issuing through the slots2'6 of the sleeve will act on the vanes 28 to rotate the sleeve in acounterclockwise direction, as shown in Fig. 4, the rotation beinglimited, however, by the engagement -of the upstanding end 36 of thespring 33 with the next projection 30 upon the sleeve. Thus, there isprovided the next degree of choke for the second shot to be fired by thegun. It will be apparent that as shown, six different positions of thechoking sleeve are provided and in each 'one of these positions exceptthe last or fullchoke position, the sleeve will be moved by thedischarge of the gun to the next higher position to give the nextgreater degree of choke.

If, however, it is not desired that the settin of the sleeve l8 bechanged by the firing of the gun, the sleeve when set is moved to theposition shown in Fig. '7 in which the end portion 36 of the spring 33lies on the opposite side of the projection 39. This will preventrotation of the sleeve by the explosion gases and as the sleeve is heldby friction against rotation in the opposite direction, the degree ofchoke will be unchanged until the sleeve is reset by the user.

While I have shown and described a preferred embodiment of my invention,it will be understood that it is not to be limited to all of the detailsshown, but is capable of modification and variation within the spirit ofthe invention and within the scope of the claims.

What I claim is:

1. Choke mechanism for firearms comprising a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limit rotationof the sleeve member, said last-mentioned means comprising a projectionon one of said members and a stop element on the other member angularlyfixed with respect thereto and movable longitudinally of said members,and spring pressed into engagement with said projection.

2. Choke mechanism for firearms comprising a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limit rotationof the sleeve member, said last-mentioned means comprising a pluralityof spaced projections on one of said members and a stop element carriedby the other member movable longitudinally of said members and springpressed into the spaces between said projections to engage the latter.

3. Choke mechanism for firearms comprising a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limit rota-'tion of the sleeve member, said last-mentioned means comprising aplurality of spaced projections on one of s'aid'members and a stopelement carried by the other member movable longitudinally of saidmembers and spring pressed into the spaces between said projections toengage the latter, said spaces being larger than said stop element topermit limited rotation of the sleeve member. I r

4. Choke mechanism for firearms comprisin a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limitrotation' of the sleeve member, said last-mentioned means comprising aplurality of spaced projections on one of said members and a spring ofarcuate shape secured at one end to the other member, the free end ofthe spring carrying a stop element movable longitudinally of saidmembers and normally standing between said projections.

5. Choke mechanism for firearms comprising a constrictable split muzzleextension, a sleeve rotatably connected to said extension, cooperatingmeans on said extensionand sleeve to constrict the former upon rotationof the latter, means responsive to discharge of the firearm for rotatingsaid sleeve, and cooperating means on said extension and sleeve to limitrotation of the sleeve, said last-mentioned means comprising a pluralityof spaced rearwardly extending projections on the rear end of the sleeveand'a spring member of arcuate shape having one end secured to saidextension, the other endof said spring member being free and carrying astop element normally standing between said projections but beingmovable longitudinally of said sleeve to clear said projections topermit rotation of the sleeve.

6. Choke mechanism for firearms comprising a constrictable split muzzleextension, a sleeve rotatably connected to said extension, cooperatingmeans on said extension and sleeve to constrict the former upon rotationof the latter, means responsive to discharge of the firearm for rotatingsaid sleeve, and cooperating means on said extension and sleeve to limitrotation of the sleeve, said last-mentioned means comprising a pluralityof spaced rearwardly extending projections on the rear end of the sleeveand a spring member of arcuate shape having one end secured to saidextension, the other end of said spring member being free and carrying astop element normally standing between said projections but beingmovable longitudinally of said sleeve to clear said projections topermit rotation of the sleeve, said extension having an exterior groovetherein in which said spring member lies.

7. Choke mechanism for firearms comprising a constrictable split muzzleextension, a sleeve rotatably connected to said extension, cooperatingmeans on said extension and sleeve to constrict the former upon rotationof the latter, means responsive to discharge of the firearm for rotatingsaid sleeve, and cooperating means on said extension and sleeve to limitrotation of the sleeve, said last-mentioned means comprising a pluralityof spaced rearwardly extending projections on the rear end of the sleeveand a spring member of arcuate shape having one end secured to saidextension, the other end of said spring membeer being free and carryinga stop element normally standing between said. projections but beingmovable longitudinally of said sleeve to clear said projections topermit rotation of the sleeve, said extension having an exterior groovetherein in which said spring member lies and wall of said groove beingcut away to permit movement of the free end of the spring member.

8. Choke mechanism for firearms comprising a constrictable split muzzleextension, a sleeve rotatably connected to said extension, cooperatingmeans on said extension and sleeve to constrict the former upon rotationof the latter, means re.- sponsive to discharge of the firearm forrotating said sleeve, and cooperating means on said extension and sleeveto limit rotation of the sleeve, said last-mentioned means comprising aplurality of spaced rearwardly extending projections on the rear end ofthe sleeve and a spring member of arcuate shape having one end securedto said extension and the other end of said spring being free and beingturned outwardly in radial direction to constitute a, stop elementnormally standing between said projections, said stop element beingmovable longitudinally of said sleeve against the tension of th springto position to clear said projections and permit rotation of the sleeve.

9. Choke mechanism for firearms comprising a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limit rotationof the sleeve member, said last-mentioned means comprising a pluralityof spaced projectio s n o e f s d mem e s and. a in o arcuate shapesecured at on end to the other member, the free end of the springcarryin a stop element movable longitudinally of said members andnormally standing between said projections and the spacing of saidprojections being such with relation to the width of said step elementthat limited rotation of said sleeve member is permitted by said stopelement to substantially vary the amount of constriction of the muzzleextension member.

10. Choke mechanism for firearms comprising a constrictable split muzzleextension member, a sleeve member rotatably connected to said extensionmember, cooperating means on said extension and sleeve members toconstrict the former upon rotation of the latter, means responsive todischarge of the firearm for rotating said sleeve member, andcooperating means on said extension and sleeve members to limit rotationof the sleeve member, said last-mentioned means comprising a pluralityof spaced means on one of said members and a stop element on the othermember movable longitudinally of said members and spring pressed intoengagement with said spaced means.

EZEKIEL F.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,892,522 White Dec. 27, 1932 2,453,747 Egleson Nov. 1.6, 19482,490,829 N011 Dec. 13, 1949 2,567,826 Prache Sept. 11, 1951 FOREIGNPATENTS Number Country Date 296,553 Germany Feb. 15, 1917

